The following time management services are available:
The tick
service enables the system
to manage the clock, counting ticks since the boot of the system. Thus the
only time available is the time elapsed since the last reboot.
The date
service enables
the ChorusOS operating system to maintain a current date, usually expressed
in seconds since the 01/01/1970. Calls to set and get the time of day are
available, through standard C libraries ctime
and localtime
, and are not detailed in this document.
The time-out
service enables
supervisor actors to set up time-outs. A time-out may be roughly described
as a callback which will be performed when a given delay has expired. Callbacks
are performed using a special invocation mechanism (called Local Access Point
or LAP) reserved for supervisor actors.
The timer
service is
an extension of the time-out mechanism, enabling user and supervisor actors
to set up call backs in a more flexible fashion.
The virtual time and time-out service allows you to measure the CPU time used by threads, and to define handlers which will be called if a per-thread or per-actor CPU quota is reached.
Table 9-1 shows which services are available for a given configuration:
Table 9-1 Time Management Service AvailabilityService | Availability |
---|---|
tick | always available |
date | configured with DATE |
time-out | always available |
timer | configured with TIMER |
virtual time | configured with VTIMER |